The present invention relates to laboratory equipment and pertains particularly to an adaptor for ground glass couplings. Chemcial laboratory equipment includes a great many glass vessels, flasks and tubing which may be coupled and uncoupled in various configurations to set up the appropriate equipment. Reducing adaptors are utilized for coupling of different size tubings and couplings different size tubings to glass flasks and the like. Such couplings and the joints between such adaptors and the tubings or vessels are usually ground glass very slightly tapered at 5 degrees 43'(known as a Standard Taper, as specified by the American Standard Testing and Manufacturing organization [ASTM]) to insure a secure fit. Such joints are usually coated with a silicon grease in order to seal the joints and prevent leakage.
For the purpose of this specification, the term stopper is defined to include a stopper having a bore opening for reducing or enlargening the diameter of glassware openings, commonly referred to in the art as adapters, and to also include a stopper having a solid body used as a plug to close glassware openings.
The problem with such ground glass adaptors is that the silicon may contaminate the test sepcimen, and upon sitting for some time adaptors and stoppers tend to freeze and can't be removed. Such silicon grease also makes clean-up time consuming and unpleasant.
It is therefore desirable that an improved coupling be available for ground glass laboratory equipment.